package com.example.demo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

public class HttpUtil {


	/**
     * 向指定URL发送GET方法的请求
     *
     * @param url
     *            发送请求的URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return URL 所代表远程资源的响应结果
	 * @throws IOException 
     */
	public static String sendGet(String url,String charset) throws Exception {

        URL realurl = new URL(url);
        String USER_AGENT = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; customie8)";
        HttpURLConnection con = (HttpURLConnection) realurl.openConnection();

 

        // optional default is GET

        con.setRequestMethod("GET");
        // add request header

        con.setRequestProperty("User-Agent", USER_AGENT);

        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream(),charset));

        String inputLine;

        StringBuffer result = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {

            result.append(inputLine);

            result.append("\r\n");

        }

        in.close();

        con.disconnect();

        return result.toString();

    }
    
    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */

    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
            		"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            System.out.println(param);
            // 发送请求参数
            out.print(param);

            // flush输出流的缓冲
            out.flush();

            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
            		new InputStreamReader(conn.getInputStream()));

            String line;
            while ((line = in.readLine()) != null) {
            	result += line;
            }
        } catch (Exception e) {

            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();

        }


        //使用finally块来关闭输出流、输入流

        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }

}



